#ifndef __ARES_PRIVATE_H
#define __ARES_PRIVATE_H

/* Copyright 1998 by the Massachusetts Institute of Technology.
 * Copyright (C) 2004-2010 by Daniel Stenberg
 *
 * Permission to use, copy, modify, and distribute this
 * software and its documentation for any purpose and without
 * fee is hereby granted, provided that the above copyright
 * notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting
 * documentation, and that the name of M.I.T. not be used in
 * advertising or publicity pertaining to distribution of the
 * software without specific, written prior permission.
 * M.I.T. makes no representations about the suitability of
 * this software for any purpose.  It is provided "as is"
 * without express or implied warranty.
 */

/*
 * Define WIN32 when build target is Win32 API
 */

#if (defined(_WIN32) || defined(__WIN32__)) && !defined(WIN32)
#define WIN32
#endif

#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif

#ifdef WATT32
#include <tcp.h>
#include <sys/ioctl.h>
#define writev(s, v, c) writev_s(s, v, c)
#define HAVE_WRITEV 1
#endif

#define DEFAULT_TIMEOUT 5000 /* milliseconds */
#define DEFAULT_TRIES 4
#ifndef INADDR_NONE
#define INADDR_NONE 0xffffffff
#endif

#ifdef CARES_EXPOSE_STATICS
/* Make some internal functions visible for testing */
#define STATIC_TESTABLE
#else
#define STATIC_TESTABLE static
#endif

#if defined(WIN32) && !defined(WATT32)

#define WIN_NS_9X "System\\CurrentControlSet\\Services\\VxD\\MSTCP"
#define WIN_NS_NT_KEY "System\\CurrentControlSet\\Services\\Tcpip\\Parameters"
#define NAMESERVER "NameServer"
#define DHCPNAMESERVER "DhcpNameServer"
#define DATABASEPATH "DatabasePath"
#define WIN_PATH_HOSTS "\\hosts"

#elif defined(WATT32)

#define PATH_RESOLV_CONF "/dev/ENV/etc/resolv.conf"

#elif defined(NETWARE)

#define PATH_RESOLV_CONF "sys:/etc/resolv.cfg"
#define PATH_HOSTS "sys:/etc/hosts"

#elif defined(__riscos__)

#define PATH_HOSTS "InetDBase:Hosts"

#else

#define PATH_RESOLV_CONF "/etc/resolv.conf"
#ifdef ETC_INET
#define PATH_HOSTS "/etc/inet/hosts"
#else
#define PATH_HOSTS "/etc/hosts"
#endif

#endif

#define ARES_ID_KEY_LEN 31

#include "ares_ipv6.h"
#include "ares_llist.h"

#ifndef HAVE_GETENV
#include "ares_getenv.h"
#define getenv(ptr) ares_getenv(ptr)
#endif

#include "ares_strdup.h"

#ifndef HAVE_STRCASECMP
#include "ares_strcasecmp.h"
#define strcasecmp(p1, p2) ares_strcasecmp(p1, p2)
#endif

#ifndef HAVE_STRNCASECMP
#include "ares_strcasecmp.h"
#define strncasecmp(p1, p2, n) ares_strncasecmp(p1, p2, n)
#endif

#ifndef HAVE_WRITEV
#include "ares_writev.h"
#define writev(s, ptr, cnt) ares_writev(s, ptr, cnt)
#endif

/********* EDNS defines section ******/
#define EDNSPACKETSZ 1280 /* Reasonable UDP payload size, as suggested \
                             in RFC2671 */
#define MAXENDSSZ 4096 /* Maximum (local) limit for edns packet size */
#define EDNSFIXEDSZ 11 /* Size of EDNS header */
/********* EDNS defines section ******/

struct ares_addr {
    int family;
    union {
        struct in_addr addr4;
        struct ares_in6_addr addr6;
    } addr;
    int udp_port; /* stored in network order */
    int tcp_port; /* stored in network order */
};
#define addrV4 addr.addr4
#define addrV6 addr.addr6

struct query;

struct send_request {
    /* Remaining data to send */
    const unsigned char* data;
    size_t len;

    /* The query for which we're sending this data */
    struct query* owner_query;
    /* The buffer we're using, if we have our own copy of the packet */
    unsigned char* data_storage;

    /* Next request in queue */
    struct send_request* next;
};

struct server_state {
    struct ares_addr addr;
    ares_socket_t udp_socket;
    ares_socket_t tcp_socket;

    /* Mini-buffer for reading the length word */
    unsigned char tcp_lenbuf[2];
    int tcp_lenbuf_pos;
    int tcp_length;

    /* Buffer for reading actual TCP data */
    unsigned char* tcp_buffer;
    int tcp_buffer_pos;

    /* TCP output queue */
    struct send_request* qhead;
    struct send_request* qtail;

    /* Which incarnation of this connection is this? We don't want to
   * retransmit requests into the very same socket, but if the server
   * closes on us and we re-open the connection, then we do want to
   * re-send. */
    int tcp_connection_generation;

    /* Circular, doubly-linked list of outstanding queries to this server */
    struct list_node queries_to_server;

    /* Link back to owning channel */
    ares_channel channel;

    /* Is this server broken? We mark connections as broken when a
   * request that is queued for sending times out.
   */
    int is_broken;
};

/* State to represent a DNS query */
struct query {
    /* Query ID from qbuf, for faster lookup, and current timeout */
    unsigned short qid;
    struct timeval timeout;

    /*
   * Links for the doubly-linked lists in which we insert a query.
   * These circular, doubly-linked lists that are hash-bucketed based
   * the attributes we care about, help making most important
   * operations O(1).
   */
    struct list_node queries_by_qid; /* hopefully in same cache line as qid */
    struct list_node queries_by_timeout;
    struct list_node queries_to_server;
    struct list_node all_queries;

    /* Query buf with length at beginning, for TCP transmission */
    unsigned char* tcpbuf;
    int tcplen;

    /* Arguments passed to ares_send() (qbuf points into tcpbuf) */
    const unsigned char* qbuf;
    int qlen;
    ares_callback callback;
    void* arg;

    /* Query status */
    int try_count; /* Number of times we tried this query already. */
    int server; /* Server this query has last been sent to. */
    struct query_server_info* server_info; /* per-server state */
    int using_tcp;
    int error_status;
    int timeouts; /* number of timeouts we saw for this request */
};

/* Per-server state for a query */
struct query_server_info {
    int skip_server; /* should we skip server, due to errors, etc? */
    int tcp_connection_generation; /* into which TCP connection did we send? */
};

/* An IP address pattern; matches an IP address X if X & mask == addr */
#define PATTERN_MASK 0x1
#define PATTERN_CIDR 0x2

struct apattern {
    union {
        struct in_addr addr4;
        struct ares_in6_addr addr6;
    } addr;
    union {
        struct in_addr addr4;
        struct ares_in6_addr addr6;
        unsigned short bits;
    } mask;
    int family;
    unsigned short type;
};

typedef struct rc4_key {
    unsigned char state[256];
    unsigned char x;
    unsigned char y;
} rc4_key;

struct ares_channeldata {
    /* Configuration data */
    int flags;
    int timeout; /* in milliseconds */
    int tries;
    int ndots;
    int rotate; /* if true, all servers specified are used */
    int udp_port; /* stored in network order */
    int tcp_port; /* stored in network order */
    int socket_send_buffer_size;
    int socket_receive_buffer_size;
    char** domains;
    int ndomains;
    struct apattern* sortlist;
    int nsort;
    char* lookups;
    int ednspsz;

    /* For binding to local devices and/or IP addresses.  Leave
   * them null/zero for no binding.
   */
    char local_dev_name[32];
    unsigned int local_ip4;
    unsigned char local_ip6[16];

    int optmask; /* the option bitfield passed in at init time */

    /* Server addresses and communications state */
    struct server_state* servers;
    int nservers;

    /* ID to use for next query */
    unsigned short next_id;
    /* key to use when generating new ids */
    rc4_key id_key;

    /* Generation number to use for the next TCP socket open/close */
    int tcp_connection_generation;

    /* The time at which we last called process_timeouts(). Uses integer seconds
     just to draw the line somewhere. */
    time_t last_timeout_processed;

    /* Last server we sent a query to. */
    int last_server;

    /* Circular, doubly-linked list of queries, bucketed various ways.... */
    /* All active queries in a single list: */
    struct list_node all_queries;
    /* Queries bucketed by qid, for quickly dispatching DNS responses: */
#define ARES_QID_TABLE_SIZE 2048
    struct list_node queries_by_qid[ARES_QID_TABLE_SIZE];
    /* Queries bucketed by timeout, for quickly handling timeouts: */
#define ARES_TIMEOUT_TABLE_SIZE 1024
    struct list_node queries_by_timeout[ARES_TIMEOUT_TABLE_SIZE];

    ares_sock_state_cb sock_state_cb;
    void* sock_state_cb_data;

    ares_sock_create_callback sock_create_cb;
    void* sock_create_cb_data;

    ares_sock_config_callback sock_config_cb;
    void* sock_config_cb_data;
};

/* Memory management functions */
extern void* (*ares_malloc)(size_t size);
extern void* (*ares_realloc)(void* ptr, size_t size);
extern void (*ares_free)(void* ptr);

/* return true if now is exactly check time or later */
int ares__timedout(struct timeval* now,
    struct timeval* check);

void ares__send_query(ares_channel channel, struct query* query,
    struct timeval* now);
void ares__close_sockets(ares_channel channel, struct server_state* server);
int ares__get_hostent(FILE* fp, int family, struct hostent** host);
int ares__read_line(FILE* fp, char** buf, size_t* bufsize);
void ares__free_query(struct query* query);
unsigned short ares__generate_new_id(rc4_key* key);
struct timeval ares__tvnow(void);
int ares__expand_name_for_response(const unsigned char* encoded,
    const unsigned char* abuf, int alen,
    char** s, long* enclen);
void ares__init_servers_state(ares_channel channel);
void ares__destroy_servers_state(ares_channel channel);
#if 0 /* Not used */
long ares__tvdiff(struct timeval t1, struct timeval t2);
#endif

#define ARES_SWAP_BYTE(a, b)           \
    {                                  \
        unsigned char swapByte = *(a); \
        *(a) = *(b);                   \
        *(b) = swapByte;               \
    }

#define SOCK_STATE_CALLBACK(c, s, r, w)                                 \
    do {                                                                \
        if ((c)->sock_state_cb)                                         \
            (c)->sock_state_cb((c)->sock_state_cb_data, (s), (r), (w)); \
    }                                                                   \
    WHILE_FALSE

#ifdef CURLDEBUG
/* This is low-level hard-hacking memory leak tracking and similar. Using the
   libcurl lowlevel code from within library is ugly and only works when
   c-ares is built and linked with a similarly curldebug-enabled libcurl,
   but we do this anyway for convenience. */
#define HEADER_CURL_SETUP_ONCE_H
#include "../lib/memdebug.h"
#endif

#endif /* __ARES_PRIVATE_H */
